1. Technical Field
Aspects of this document relate to combination water leveling devices for use in swimming pools.
2. Background Art
Conventional swimming pool water leveling devices include very simple direct operated float valves, pilot operated float valves, and various forms of electronic sensor controlled electric valves. A secondary reservoir that is in fluid communication with the pool is normally located adjacent to the pool. The fluid level in the secondary reservoir is typically maintained equal to the pool level through an inter-connection pipe. As the water level in the pool changes, the level in the adjacent water reservoir changes to equalize to the pool. A fill valve is typically mounted in the secondary reservoir to sense the water level and add water as required to maintain the water at a preset level. In the case of electronic devices, the sensor may be located with-in or adjacent to the pool and the fill water is introduced directly into the pool at another location. It is common to adapt the secondary reservoir with an overflow pipe through which excess water in the pool, such as from a rain storm, can overflow and gravity drain from the pool.
Many conventional swimming pool water leveling devices experience rapid water level fluctuation in the secondary reservoir due to activity in the pool or the water supply valve opening. This causes rapid on/off action of the water supply valving mechanism. This results in objectionable water hammer in the water supply valve and rapid wear of the valve. In the case of electronic automatic leveling devices, complicated and expensive electronic controls are employed to minimize excessive opening/closing of the water supply valve. Direct operating float valves, similar to those used in evaporative coolers, are dependable and do not cause water hammer through the opening and closing of the valve. However, direct operating float valves are difficult to replace within the reservoir and are very difficult to adjust to the desired water level, often requiring a service professional to make several separate and costly calls to achieve a proper level setting. Additionally, because of the relatively long operating arm required for direct operating valves, the secondary reservoir is necessarily large enough to house the long operating arm. This is a disadvantage for pool owners concerned with the large, unsightly opening in the pool deck.
Pilot operated valves, similar to those used in toilet reservoir tanks, can be used in a smaller secondary reservoir and are, thus, less aesthetically objectionable. Because these valves are pilot operated, delicate diaphragms and very small fluid control orifices are used. However, the small orifices used in the pilot operated valves yield troublesome operation due to the swimming pool environment. Level adjustment in pilot operated valves is typically achieved by some sort of screw or slidable adjuster which is an improvement over the adjustability of the direct operating float valve types. Pilot valves generally experience water hammer and rapid wear of the valve as the valve cycles on and off. To overcome the water hammer condition, the input water source is often severely restricted by installing a small orifice in the supply source. This results in slower filling of the swimming pool.
Electronic water level controllers are very expensive compared with other mechanical devices, and generally involve very complicated installations. Pilot operated valves are usually employed in such systems along with an electronic sensor and control system.
In conventional swimming pool systems, the balance line cannot be pressure tested and the overflow line is generally not pressure tested because of the difficulty in blocking each of the separate sections of the lines and connecting the testing apparatus to each. However, if the various water lines are not pressure tested, they may have leaks which can cause swelling of the soil and in extreme cases breakage of the pool in concrete pools.